Grind cashewnuts, almonds and pistachios to a coarse powder. Chop dried figs and dates into small pieces.
Heat ghee in a non stick pan, add the ground nuts, figs and dates and sauté for 2-3 minutes. Add 2 cups water and mix well.
Melt dark chocolate in a double boiler.Add khoya and raisins to date mixture and mix well.
Transfer into a bowl and set aside to cool. Melt white chocolate in a double boiler.
Spread date mixture on a biscuit and cover it with another biscuit. Use up all the biscuits and date mixture thus.
Prick each sandwich on a fork, and pour dark chocolate over it. Place the biscuit sandwiches in a plate and refrigerate for 10-15 minutes.
Turn the biscuits over and pour white chocolate on the other side. Refrigerate again for 10-15 minutes till the chocolate sets. Serve chilled.